This invention relates to a bendable actuator of an air-bag type, which is extensible in curving when a pressurized fluid is supplied into the actuator.
Electric motors, hydraulic cylinders, and the like have been known as actuators for transferring electric energy or energy in pressurized fluids into mechanical energy.
However, an electric motor usually requires a speed reduction mechanism including gear trains to thereby increasing the weight and space to be occupied by the motor. Moreover, due to sparks unavoidably occurring in operation, the use of the motor in an explosive atmosphere is extremely limited.
On the other hand, in the case of a hydraulic cylinder, in addition to the abovementioned problems, it is difficult to completely prevent leakage of operating oils so that environmental contamination by the leaked oils could not be avoided. Moreover, the temperature and purity of the operating oils must be finely managed. As a result, in order to obtain a high power actuator of the hydraulic cylinder type, it will become inevitably large sized.
Moreover, output shafts of the electric motors and hydraulic cylinders are only allowed to perform rotary or linear movements.